The situations aren't analogous. The US has neither the resources nor the technology available within the UFP.

A more analogous situation might be if you moved into a house located near an airport, knowing full well that the airport might be able to buy you out at some point, and then they exercised that right.

George Steinbrenner wrote:

^ And if you had a hundred or so different locations all ready for you to move to.

Assuming there were a hundred or so different locations all ready for them to move to and ample ships to do it with, we don't know how big the colony populations were or how many M-class planets the federation had available to just move people to (since they terraforms planets its probably not an infinite supply).